Infeed and sealing means for grinding mills



p 17, 1968 v J. A. REYNOLDS 3,401,893

INFEED AND SEALING MEANS FOR GRINDING MILLS Filed July 11, 1966 Z'Sheets-Sheet l I NVENTOR.

JAMES A .REY/VOLOS ATTORNEYS p 7, 1968 J. A. REYNOLDS 3,401,893

INFEED AND SEALING MEANS FOR GRINDING MILLS Filed July 11, 1966 2 Sheets-Sheet 2 I NVENTOR.

JAMES A. HEY/vows ATTORNEYS United States Patent 3,401,893 INFEED AND SEALING MEANS FOR GRINDING MILLS James A. Reynolds, Silver Bay, Minn., assignor to Reserve Mining Company, Silver Bay, Minn., a corporation of Minnesota Filed July 11, 1966, Ser. No. 564,164 10 Claims. (Cl. 241171) This invention relates generally to grinding mills of the type including a generally cylindrical drlun rotatable on a generally horizontal axis and adapted to receive at one end a mixture of material, such as ore previously crushed or ground to a predetermined size range, and liquid, hereinafter designated as a slurry; and to further reduce or pulverize the material with the aid of rods or balls of hardened metal tumbling about within the drum, and to discharge the slurry from the other end of the drum.

More particularly, this invention relates to feeding and sealing means for a grind mill of this type, the drum including a hollow axial trunnion supported for rotation with the drum by a bearing, and provided with a removable tubular liner having a frusto-conical inner wall surface coaxial with the trunnion and converging toward the outer end of the trunnion. The liner is releasably locked in the trunnion for common rotation therewith. A stationary tubular infeed conduit has a discharge end portion extending axially inwardly of the outer reduced diameter end of the liner and terminates in an open end intermediate the opposite ends of the liner.

Sealing means encompasses the discharge end portion of the conduit intermediate the open discharge end and the outer end of the liner, and is removably mounted therein to prevent leakage of slurry outwardly of the infeed end of the drum. The sealing ring means is axially spaced a substantial distance from the open discharge end of the conduit so as to be isolated from the flow of slurry from the conduit to the interior of the drum.

Heretofore, various arrangements for feeding slurry to a ball or rod mill utilized open troughs feeding directly into the grinding drum or into rotary cylindrical feeding drums axially outwardly of the grinding drum, these feeding drums having scoops for moving the slurry toward the interior of the grinding drum. Such open feed troughs are difiicult to seal against leakage of slurry at the infeed end of the grinding drum, as is the connection between the feeding drum and the grinding drum, when such feeding drums are used. Moreover, considerable power is expended in imparting feeding rotation to a feed drum.

An important object of this invention is the provision of feeding means for a grinding mill which consumes substantially none of the power required to operate the grinding mill.

Another object of this invention is the provision of feeding and sealing apparatus by means of which slurry is fed axially into the grinding drum and which effectively prevents leakage of slurry or slurry liquid from the infeed end of the drum.

Another object of this invention is the provision of sealing means between a stationary feeding conduit and a rotary trunnion liner, which is not subject to the direct flow of slurry from the conduit into the drum.

Still another object of this invention is the provision of a novel arrangement whereby the feeding means, sealing means and liner means may be quickly and easily removed for replacement or service, and as quickly and easily replaced.

Yet another object of this invention is the provision of sealing means as set forth which permits mis-alignment or appreciable eccentricity between the infeed conduit portion within the trunnion liner and the liner, or appreciable eccentric movement of the grinding drum and trunnion, without loss of sealing effect.

Another object of this invention is the provision of novel means for feeding balls to the grinding drum.

The above, and still further highly important objects and advantages of this invention will become apparent from the following detailed specification, appended claims and attached drawings.

Referring to the drawings, in which like reference characters indicate like parts throughout the several views:

FIG. 1 is a fragmentary view in vertical section, taken substantially through the axis of the infeed end of a rod or ball mill, showing my novel feeding and sealing means;

FIG. 2 is an enlarged fragmentary view corresponding to a portion of FIG. 1; and

FIG. 3 is an enlarged fragmentary transverse section taken substantially on the line 3-3 of FIG. 1.

Referring with greater detail to the drawings, the infeed end portion of a cylindrical grinding mill is shown as comprising a cylindrical wall 1, a head end wall 2, and a hollow trunnion 3 extending axially outwardly from the head end wall 2. A ring gear 4 is bolted or otherwise rigidly secured to a mounting flange 5 on the head end wall 2 and may be assumed to have meshing engagement with a drive pinion, shown by dotted lines in FIG. 1, and indicated at 6, the drive pinion -6 being mounted on a drive shaft 7, also shown by dotted lines in FIG. 1, the shaft 7 being suitably connected to a drive motor, not shown. The head end wall 2 of the grinding cylinder is provided with an annular lining 2a that is removably secured to the head end wall 2 by nut equipped bolts or the like 2b.

The grinding mill or drum is journalled for rotation on a generally horizontal axis in end bearings 8, one of which is shown. As illustrated in FIGS. 1 and 3, the bearing 8 is mounted on a supporting pillar 9, the bearing 8 comprising a semi-circular bearing element 10, a half sleeve 11 carried by the bearing element 10 and engaging the lower one-half of the outer peripheral surface of the trunnion 3, and a semi-circular retaining cap 12 which overlies the upper peripheral one-half of the trunnion 3 and which is bolted to a lower housing portion 13 that is anchored to the pillar 9. Bearing cap 12 and housing portion 13 cooperate to define a lubricant chamber 14 encompassing the trunnion 3 and closed at opposite end portions of the trunnion 3 by suitable annular oil seals 15. Mounted on pillar 9 within housing portion 13 to support bearing element 10 is a bearing support 13a.

Slurry, comprising fragmented ore and liquid, such as water, is fed to the interior of the grinding mill through a conduit 16 comprising a plurality of conduit sections 17 connected together by flanged coupling elements 18 and a delivery section 19 having a leg portion 20 that is connected to the adjacent section 17 and extends angularly upwardly whereby the slurry flows by gravity to the grinding drum. The conduit section 19 further includes a tubular discharge end portion 21 disposed substantially coaxial with the trunnion 3 and which extends axially into trunnion liner means 22 within the trunnion 3. The liner means 22 comprises a frusto-conical fitting 23 having axially inner and outer radially outwardly projecting flanges 24 and 25 respectively, and a frusto-conical liner element 26 that fits within and is tack welded or otherwise rigidly secured to the fitting 23, as indicated at 27, see particularly FIG. 2, preferably at circumferentially spaced points about the outer surface of the liner element 26. As shown in FIGS. 1 and 2, the liner element 26 converges in a direction axially outwardly relative to the trunnion 3, the inner large diameter end of the liner element 26 being disposed substantially even with the axially inner end 28 of the fitting 23, the reduced diameter axially outer end of the liner element 26 extending axially beyond the axially outer end of the fitting 23 defined by the flange 25 thereof. The peripheral edge surfaces of the flanges 24 and 25 slidingly engage the inner cylindrical surface of the trunnion 3, axially inward movement of the liner means 22 being limited by an annular stop flange 29 projecting radially inwardly from the inner cylindrical surface of the trunnion 3 adjacent the head and wall 2, see FIG. 2. A plurality of packing rings 30 encompass the axially inner end 28 of the fitting 23 and are adapted to be axially compressed between the flanges 24 and 29 to seal the interior of the trunnion 3 from liquid within the grinding mill. Although a gap 31 normally exists between the inner end 28 of the fitting 23 and the adjacent portion of the annular lining 2a, another sealing means such as a packing ring could be used in gap 31. The inner means 22 is releasably locked within the trunnion 3 for common rotation therewith by a generally cylindrical locking ring 32 the axially inner end of which engages the flange 25, the locking ring 32 including a radially outwardly projecting annular flange 33 that is releasably anchored to the outer end of the trunnion 3 by circumferentially spaced nut-equipped studs 34, see FIGS. 1 and 2. Thus, the liner means 22 is held against axial movement in the trunnion 3 by the stop flange 29 and packing rings 30 at one end and by the locking ring 32 at the other end of the fitting 23. It should be noted that locking ring 32 could be formed in one piece with flange 25. Whether ring 32 is a separate piece or not is a matter of choice.

Means for preventing leakage of liquid from the interior of the grinding drum axially outwardly between the tubular conduit discharge portion 21 and the liner element 26 comprises an elastic sealing ring 35 and a packing ring 36. The sealing ring 35 is in the nature of a normally flat annular washer made from elastic rubberlike sheet material and having an inner diameter substantially less than the outer diameter of the conduit discharge end portion 21. The sealing ring 35 is detachably secured to one side of a radially inwardly projecting annular flange 37 that is welded to the radially inner surface of the liner element 26, by means of an annular anchoring ring 38 and a plurality of nut-equipped screws or the like 39 extending through the sealing ring 35 adjacent its outer peripheral edge, the anchoring ring 38 and flange 37, see particularly, FIG. 2. The normal flat disposition of the sealing ring 35 is shown by dotted lines in FIG. 2. When the discharge end portion 21 of the delivery conduit 16 is moved axially into the liner means 22, the inner diameter portion of the sealing ring 35 stretches, the ring 35 assuming the full line position shown in FIG. 2. With the inner diameter portion thereof being in a stretched condition, the same snugly encompasses the conduit portion 21 to provide an effective seal against escape of liquid or other material outwardly therebetween. It should here be noted that the flange 37 is Welded to the inner surface of the liner element 26 throughout the entire outer peripheral edge of the flange 37 so that no leakage occurs therebetween and the liner element 26.

A generally cylindrical seat element 40 is welded to the axially outer face of the anchoring flange 37 and concentric to the axis thereof, the seat element 40 projecting axially outwardly from the anchoring flange 37. An annular clamping ring 41 is bolted or otherwise removably secured to an annular mounting flange 42 projecting radially outwardly of the axially outer end of the liner element 26, the clamping ring 41 cooperating with the cylindrical seat 40 and anchoring flange 37 to define a radially inwardly opening channel for reception of the packing ring 36. It will be noted, with reference particularly to FIG. 2, that the inner diameters of the anchoring flange 37 and clamping ring 41 are somewhat larger than the outer diameter of the conduit end portion 21 extending therethrough, whereby to allow for eccentricity or misalignment between the relatively stationary conduit portion 21 and the rotating parts surrounding the same. The packing ring 36 is made from resilient compressible material, and may be one of any of the types readily available in the market. The elasticity and resilience of the sealing ring 35 and packing ring 36 provides for an eflicient seal therebetween and the conduit portion 21 even during eccentric rotation of the grinding mill relative to the conduit portion 21, should such a condition occur. If desired, axial compression of the packing ring 36 may be increased with the use of one or more spacing washers 43, one of which is shown in FIG. 2. Should leakage occur between the rings 35 and 36 and the infeed conduit portion 21, because the rings are worn, a frusto-conical drip flange 44 directs the liquid outwardly away from the bearing 8, as does a second drip ring 45 mounted on the flange 33 on the locking ring 32.

With reference to FIG. 1, it will be seen that the conduit portion 21 extends axially into the liner means 22 for generally one-half the axial length of the liner element 26, the conduit portion 21 terminating in an open end 46 axially inwardly spaced a substantial distance from the sealing ring 35. A plurality of circumferentially spaced radially inwardly projecting feeding vanes 47 are welded or otherwise rigidly secured to the inner surface of the liner element 26 and extend axially from the inner end of the liner element 26 in a generally helical direction, terminating at their opposite ends intermediate the open end 46 of the conduit portion 21 and the sealing ring 35. The vanes 47 are so disposed to direct slurry toward the interior of the grinding mill drum responsive to rotation of the grinding mill and aids substantially in keeping the incoming slurry away from the sealing ring 35 and packing ring 36. It will be appreciated that the normal level of slurry within the grinding mill is somewhat below the axis of the grinding mill, the normal operating level of the slurry being indicated by the line A in FIG. 1.

Although feeding vanes 47 are used in the preferred embodiment shown and described herein, such vanes can be eliminated without impairing the useful operation of my invention. Vanes 47 are normally used with rod mills where the slurry is usually very dense. In the case of ball mills, where the slurry is usually much less dense, vanes 47 can be eliminated, if desired.

During operation of a ball mill, the balls become worn over extended periods of use, and the supply thereof must be periodically replenished. For this purpose, I provide a supply hopper 48 that is connected to one of the conduit sections 17 by a branch conduit 49 in which is interposed a valve shown diagrammatically in FIG. 1 and indicated at 50. A supply of grinding balls or the like 51 is shown within the hopper 48. When it is desired to add to the sup ply of grinding balls within the mill, it is only necessary to open the valve 50 to permit the balls 51 to drop into the conduit 16, the balls 51 descending into the grinding mill by gravity.

Because of the abrasive quality of some ores, the conduit section 19 is subject to relatively rapid wear, and must be periodically changed. Liner element 26 is also subject to wear and must be periodically replaced, although not as often as conduit section 19. With the arrangement above-described, it is a simple and relatively inexpensive matter to remove and replace the liner means 22 and conduit section 19, by removing the locking ring 32 and disconnecting the tubular conduit section 19 from its adjacent conduit section 17. If desired, and due to'the fact that the liner element 26 is tack welded to the fitting 23, the fitting 23 may be easily provided with a new liner element 26 and replaced in the trunnion 3. Further, the abovedescribed construction provides for relatively quick and easy replacement of the sealing ring 35 and packing ring 36, when such replacement is necessary.

While I have shown and described a commercial embodiment of my novel feeding and sealing means for grinding mills, it will be understood that the same is capable of modification, without departure from the spirit and scope of the invention, as defined in the claims.

What is claimed is:

1. In a grinding mill comprising, a generally cylindrical wall, a head end wall, a hollow trunnion projecting axially from said head end wall, and means for rotatably supporting said drum on a generally horizontal axis including a bearing at least partially encompassing said trunnion:

(a) tubular liner means disposed in said trunnion coaxially therewith and having axially inner and outer ends,

(b) means for releasably locking said liner means within said trunnion for common rotation therewith and against axial movements relative thereto,

(c) a stationary tubular infeed conduit having a discharge end portion substantially concentric with said liner means and terminating in an open end disposed axially inwardy of the outer end of said liner means,

(d) flexible sealing ring means disposed within said liner means and encompassing said conduit discharge end portion in sealing engagement therewith in axially spaced relation to said open end,

(e) and mounting means for removably mounting said sealing ring means in sealing engagement with said liner means and for relative rotation between said sealing ring means and one of said conduit and liner means.

2. The grinding mill defined in claim 1 in which said liner means defines a frusto-conical inner wall surface converging toward the axially outer end of said liner means, said liner means being substantially co-extensive in axial length with said trunnion, the larger diameter inner end of said inner wall surface being disposed adjacent said head end wall, said sealing ring means being disposed adjacent the outer smaller diameter end of said inner Wall surface.

3. The grinding mill defined in claim 2 characterized by a plurality of circumferentially spaced feeding vanes projecting radially inwardly from said inner wall surface and extending from the axially inner end of said wall surface toward the outer end thereof in a general helical direction and having outer ends terminating in axially spaced reationship to said sealing ring means, said open end of the conduit being disposed axially inwardly of said outer ends of the feeding vanes.

4. The grinding mill defined in claim 8 in which said mounting means includes an annular flange projecting radially inwardly from said inner wall surface adjacent the outer end of said inner wall surface and defining axially inner and outer annular sides and a central opening coaxial with said liner means and of a diameter substantially larger than the outer diameter of said conduit discharge end portion, said sealing ring means comprising an elastic annular seal element removably secured in face-to-face engagement to one side of said annular flange, said seal element defining a central opening having a normal diameter substantially less than the outer diameter of said conduit discharge end portion.

5. The grinding mill defined in claim 4 in which said seal element is secured to said axially inner side of said annular flange, said mounting means further including an annular clamping ring disposed in axially outwardly spaced relation to said annular flange, and a generally cylindrical seat between said flange and clamping ring and secured to one of said flange and ring concentric therewith, said clamping ring defining an axial opening of a diameter substantially equal to that of said flange opening and cooperating with said cylindrical seat and said flange to define a radially inwardly opening channel, said sealing ring means further including a packing ring disposed in said channel and having sealing engagement with said conduit end portion axially outwardly of said seal element, said clamping ring being removably secured to said liner means.

6. The grind mill defined in claim 1 in which said hollow trunnion defines a cylindrical inner surface and an annular stop flange projecting radially inwardly from said cylindrical inner surface at the axially inner end of said trunnion, said liner means including a radially outwardly projecting annular stop flange in axially spaced relation to the axially inner end of said liner means and slidably engaging said inner surface of said trunnion, characterized by an annular compressible sealing ring disposed between said stop flanges and compressed therebetween when said liner means is locked in said trunnion.

7. The grinding mill defined in claim 1 in which said trunnion defines a generally cylindrical inner surface, and in which said liner means comprises a frusto-conical liner element and a fitting encompassing said liner ele ment and secured thereto, said fitting including a pair of auxiliary spaced inner and outer radially projecting annular flanges slidably engaging said inner surface of the trunnion, said trunnion including a radially inwardly projecting annular stop flange adjacent its axially inner end, said means for releasably locking the liner means within said trunnion comprising a locking ring having spaced portions, one of which is releasably secured to the axially outer end of said trunnion and the other of which engages the outer one of said fitting flanges to limit movement of said liner means axially outwardly of said trunmon.

8. The grinding mill defined in claim 7 characterized by an annular compressible sealing ring disposed between said inner fitting flange and said stop flange and compresses therebetween when said locking ring is secured to said trunnion.

9. The grinding mill defined in claim 1 in which said infeed conduit comprises a plurality of pipe sections at least one of which slopes upwardly relative to said discharge end portion, said discharge end portion including an angularly displaced tubular leg axially outwardly of said sealing ring means in alignment with said one of the sections and releasably secured thereto.

10. The grinding mill defined in claim 9 characterized by a branch pipe extending upwardly from one of said pipe sections, a supply hopper for grinding elements connected to said branch pipe, and a valve controlling discharge of said grinding elements from said hopper to said one of the pipe sections.

References Cited UNITED STATES PATENTS 2,368,137 1/1945 Harmon 277-l87 X FOREIGN PATENTS 658,546 2/ 1963 Canada.

ANDREW R. JUHASZ, Primary Examiner. 

1. IN A GRINDING MILL COMPRISING, A GENERALLY CYLINDRICAL WALL, A HEAD END WALL, A HOLLOW TRUNNION PROJECTING AXIALLY FROM SAID HEAD END WALL, AND MEANS FOR ROTATABLY SUPPORTING SAID DRUM ON A GENERALLY HORIZONTAL AXIS INCLUDING A BEARING AT LEAST PARTIALLY ENCOMPASSING SAID TRUNNION: (A) TUBULAR LINER MEANS DISPOSED IN SAID TRUNNION COAXIALLY THEREWITH AND HAVING AXIALLY INNER AND OUTER ENDS, (B) MEANS FOR RELEASABLY LOCKING SAID LINER MEANS WITHIN SAID TRUNNION FOR COMMON ROTATION THEREWITH AND AGAINST AXIAL MOVEMENTS RELATIVE THERETO, (C) A STATIONARY TUBULAR INFEED CONDUIT HAVING A DISCHARGE END PORTION SUBSTANTIALLY CONCENTRIC WITH SAID LINER MEANS AND TERMINATING IN AN OPEN END DISPOSED AXIALLY INWARDY OF THE OUTER END OF SAID LINER MEANS, (D) FLEXIBLE SEALING RING MEANS DISPOSED WITHIN SAID LINER MEANS AND ENCOMPASSING SAID CONDUIT DISCHARGE END PORTION IN SEALING ENGAGEMENT THEREWITH IN AXIALLY SPACED RELATION TO SAID OPEN END, (E) AND MOUNTING MEANS FOR REMOVABLY MOUNTING SAID SEALING RING MEANS IN SEALING ENGAGEMENT WITH SAID LINER MEANS AND FOR RELATIVE ROTATION BETWEEN SAID SEALING RING MEANS AND ONE OF SAID CONDUIT AND LINER MEANS. 